1. Field
The present invention generally relates to data processing. More particularly, the present invention relates to providing a language for defining services.
2. Background and Material Information
Advances or changes in how enterprises conduct business result from, for example, growing competition and globalization, mergers and acquisition, or a revamping of business models. Successful advances and changes often depend on how quickly the enterprise's information technology (IT) organization adapts to evolving business needs.
For organizations to enable business advances and changes, they must ensure that enterprise applications are not only high-performance business engines driving efficiencies, but also that the applications become flexible building blocks of future business systems. Recently, building blocks have taken the form of “services.” A service, such as a Web service (or program), represents a self-contained, self-describing piece of application (program) functionality that can be found and accessed by other applications. A service may be self-contained because the application using the service does not have to depend on anything other than the service itself, and may be self-describing because all the information on how to use the service can be obtained from the service itself. The descriptions may be centrally stored and accessible through standard mechanisms. Moreover, instead of requiring programmers to establish and maintain links between applications, services may be loosely coupled, making connections simpler and more flexible and allowing applications to more easily find and understand services offered by other applications.
A user may interact with a service by “calling” the service. The call may include a text message formatted in accordance with XML (eXtensible Markup Language) and WSDL (Web Services Description Language). XML is a data format for publishing and exchanging information such as a message, on the Internet or an intranet. WSDL is an XML-based format for describing a service, such as a Web service. The WSDL standard is available at www.w3.org (see, e.g., Web Services Description Language (WSDL) 1.1, W3C Note, 15 Mar. 2001, by Erik Christensen, Francisco Curbera, Greg Meredith, and Sanjiva Weerawarana). WSDL enables definitions that describe how to access a Web service and what operations the Web service will perform. However, WSDL provides a very basic mechanism for defining a Web service. As such, there is a need to enhance WSDL.